Answer: mystery shopper
Step-by-step explanation:
From the question, we are informed that Natalie is a senior executive of a department store chain and that every week, she visits one of the stores and pretends to be a customer as she records her observations on the service provided by the store's sales associates and the manner in which her queries were handled.
We are further told that sales associates who meet the service standards are awarded a small bonus. This shows that Natalie is a mystery shopper. Mystery shoppers simply evaluate product quality, store presentation, cleanliness etc during their shopping experience.